Bushing



July 15, 1930. Q D, PI I 3,770,582

BUSHI Filed J l 9' 1928 CUF We/ded a f f Bear/Hg Surface ATTORNEYS.

Patented Jul 15, 1930 UNITED STATES PATENT OFFICE.

ROBERT D.

PIKE, OF PIEDMONT, CALIFORNIA, ASSIGNOB TO KALIF CORPORATION, 01EMEBYVILLE, CALIFORNIA, A CORPORATION 01' DELAWARE nusnme Applicationfiled July 9, 1888. Serial No. 291,459.

My present invention relates to bearing bushings and has for its objectthe provision of a bushin having new, novel, and useful characteristics.

- Another object of my invention is to provide a novel method wherebythe alloys contemplated by my bushing may be practically and effectivelyunited.

. Both ractice and laboratory tests have shown tliat the higher gradeanti-friction metals are relatively soft and lacking in both tensile andcom ressive strength. Babbitt is a well known, high grade bearing metal,and recognition of the above fact has led to a well established practicefor making bushings of an outer shell of bronze, for example, containing80% copper, 10% tin and 10% lead, with an inner shell of babbittsecurely sweated onto the inner face of the bronze bushing. The functionof the bronze is two-fold, (1)

it supports the babbitt and (2) it provides a plastic buffer between thebabbitt and the steel supporting member. Recent ex eriments performed byme show that ha bitt should be supported by a relatively soft, plasticmetal, particularly when the babbitt shell is thin. If the thin shell ofbabbitt is supported by a still steel bushing, there is a greatertendency for the bearing to heat up in service, than is the case whenthe thin layer of babbitt is supported by a plastic ring of metal whichcan absorb the journal vibrations. without undue heating. This showsthat a recent tendency to cast very thin shells of babbitt inside ofconnecting rod bearings of high speed gas engines is based upon a wrongprinciple. Another bearing metal which possesses the highest gradeanti-friction properties is an alloy of copper and lead,

usually containing 75% of copper and of lead. Some difiiculty arises inpractice in making macroscopically non-segregated castings of copper andlead, but it can be done with proper precautions and, probably, the bestknown way foraccomplis ing this is by the use of centrifugal casting.

These copper-lead alloys are, like babbitt, physically weak and on thisaccount, do not alone make suitable bearing bushin s.

so In a concurrently filed application or Letlatter, forming the innershell, will become securely welded to the outer shell of the stiff ercopper-iron-lead alloy. I thus produce a virtual one-piece bearlngbushing, which possesses an inner shell of the excellent antifrictionalloy, copper-lead, and an outer supporting shell of the stiffer, thoughrelatively plastic metal, copper-iron-lead. After machinin and assemblinthis bushing makes a bearing bushing of t e finest type, which isdesigned upon correct, scientific principles, and which can be directlyemployed in the main shaft bearings and connecting rod bearings of highspeed, high duty gas engines. These bearmgs cost less and will givelonger life than resent available bearings made from babbitt, backed bybronze.

For the purpose of facilitating an explanation of my present invention,I have prepared a drawing which illustrates the construction of mybushing. In this drawing the views are in section. In Figure 1 I show abushing or shell which may be made suitably of an allo containing copper60%, iron 38%, lea 2%; or, copper 60% iron 35% lead 5%; or copper 69%,iron 18%, lead 13%; or from intermediate compositions, as covered by theabove mentioned concurrently filed application for Letters Patent. Theinn er shell is preferably made of an allo containing 75% copper and 25%lead, although considerable variation in this latter analysis ispermissible.

A variation of my invention is shown in Figure 2. This is the samebushing shown igure 1, except there is sweated onto the inside surfaceof the copper-lead alloy a very thin shell of babbitt, usually about.015 of an inch thick. The copper-lead alloy is actually a betteranti-friction metal than the babbitt, and the only reason for using theof variable com latter is to provide an easily melting alloy which willgave way, if lubrication fails, before anything more serious can happento the en ne. I have found that when a thin shell 0 babbitt is thus suported by another soft and plastic metal li e the copper-lead alloy, itenjoys superior advantages as an anti-friction metal.

.As a result of my invention, I am able to produce bearing bushingswhich possess better anti-friction properties and at a lower cost thanis now possible.

In the claims, wherever I employ the words copper-iron-lead, I refer toan alloy ition, as covered in my concurrently file application abovereferred to, and which may also contain relativel small amounts of othermetals; and when refer to the alloy copper-lead I refer to an alloywhich usually contains copper and 25% lead, butwhose composition mayvary as between copper and lead over a considerable range .and which mayalso contain relatively small amounts of other metals. Whereever theword babbitt is used, I refer to white anti-friction metals either ofthe high tin or high lead series.

While I have shown the preferred form of my invention as now known tome, it is to be understood that various changes may be made in itsconstruction without departing from the spirit of the invention asdefined in the appended claims. a

Having thus described my invent-ion,-What I claim and desire to secureby Letters Patent 1. A bushing composed of an outer shell ofcopper-iron-lead alloy, and an inner shell of,,copper.-lead alloy, thetwo shells being 'welded together at their faces of contact to form avirtually one-piece bushing.

2. A bushing composed of an outer shell of copper-iron-lead alloy, aninner shell of copper-lead alloy welded thereto at their faces ofcontact to form'a virtually one-piece bushing, and having secured ontoits inner face a thin shell of babbitt.

3. As an article of manufacture, a bushing comprised of a layer ofrelatively infusible copper-lead alloy welded to a backing of strongersupporting metal.

4. As an article of manufacture, a bushing comprised of a layer ofrelatively infusible copper-lead alloy cast into welded engagement witha back of stifi'er metal, having a copper base.

..5. As anarticle of manufacture, a bushing comprised -ofa layer ofrelatively infusible copper-lead alloy cast into Welded engagement witha backing of stiffer metal, having substantially the same coeflicient ofthermal expansion as the copper-lead alloy.-

'6. A-bushing comprised of a layer of relatively: infusible copper-leadalloy welded to expansion.

ROBERT D. PIKE.

DISCLAIMER '1,770,582.RobertD. Pike, Piedmont, Calif. BUSHING. Patentdated Julv 15, 1930.

Disclaimer filed March 15, 1933, by the assignee, Kalzlf Corporation.Hereby enters this disclaimer to that part of the claim in saidspecification, namely, claim 3, which is in the following words, to-wit:

3. As an article of manufacture, a bushing comprised of a layer ofrelatively infusible copper-lead alloy Welded to a backing of strongersupporting metal. except when the backing of stronger supporting metalmentioned in said claim consists of an alloy of copper.

[Ofiicial Gazette April 11, 1983.]

